Benzo(a)pyrene and synthetic derivatives have been used to explore the repertoire of responses of oocytes to direct and indirect acting mutagens. Intraovarian injection demonstrates that the ovary contains the enzymes necessary to metabolize this family of xenobiotics to gametotoxic products capable to producing oocyte destruction. Analysis of the dose-response curves suggests that the rate limiting step in activation of benzo(a)pyrene is formation of the 7,8-diol-9,10-epoxide from the 8,8-diol. There are striking similarities, as well as differences between the enantiomeric forms of the diolvepoxides in bacterial and mammalian cell mutagenicity, carcinogenicity, and potency for oocyte destruction. At the present time there is no extensively validated, easily conducted assay for female germ cell response to mutagens. The data collected in this program suggests that analysis of oocyte destruction by xenobiotics may be useful for determining female germ cell response to mutagens.